1 /*
2      This file is part of libmicrohttpd
3      Copyright (C) 2007 Christian Grothoff (and other contributing authors)
4 
5      This library is free software; you can redistribute it and/or
6      modify it under the terms of the GNU Lesser General Public
7      License as published by the Free Software Foundation; either
8      version 2.1 of the License, or (at your option) any later version.
9 
10      This library is distributed in the hope that it will be useful,
11      but WITHOUT ANY WARRANTY; without even the implied warranty of
12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13      Lesser General Public License for more details.
14 
15      You should have received a copy of the GNU Lesser General Public
16      License along with this library; if not, write to the Free Software
17      Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
18 */
19 
20 /**
21  * @file fileserver_example.c
22  * @brief example for how to use libmicrohttpd to serve files (with directory support)
23  * @author Christian Grothoff
24  */
25 
26 #include "platform.h"
27 #include <dirent.h>
28 #include <microhttpd.h>
29 #include <unistd.h>
30 
31 #define PAGE "<html><head><title>File not found</title></head><body>File not found</body></html>"
32 
33 static ssize_t
file_reader(void * cls,uint64_t pos,char * buf,size_t max)34 file_reader (void *cls, uint64_t pos, char *buf, size_t max)
35 {
36   FILE *file = cls;
37 
38   (void) fseek (file, pos, SEEK_SET);
39   return fread (buf, 1, max, file);
40 }
41 
42 static void
file_free_callback(void * cls)43 file_free_callback (void *cls)
44 {
45   FILE *file = cls;
46   fclose (file);
47 }
48 
49 static void
dir_free_callback(void * cls)50 dir_free_callback (void *cls)
51 {
52   DIR *dir = cls;
53   if (dir != NULL)
54     closedir (dir);
55 }
56 
57 static ssize_t
dir_reader(void * cls,uint64_t pos,char * buf,size_t max)58 dir_reader (void *cls, uint64_t pos, char *buf, size_t max)
59 {
60   DIR *dir = cls;
61   struct dirent *e;
62 
63   if (max < 512)
64     return 0;
65   do
66     {
67       e = readdir (dir);
68       if (e == NULL)
69         return MHD_CONTENT_READER_END_OF_STREAM;
70   } while (e->d_name[0] == '.');
71   return snprintf (buf, max,
72 		   "<a href=\"/%s\">%s</a><br>",
73 		   e->d_name,
74 		   e->d_name);
75 }
76 
77 
78 static int
ahc_echo(void * cls,struct MHD_Connection * connection,const char * url,const char * method,const char * version,const char * upload_data,size_t * upload_data_size,void ** ptr)79 ahc_echo (void *cls,
80           struct MHD_Connection *connection,
81           const char *url,
82           const char *method,
83           const char *version,
84           const char *upload_data,
85 	  size_t *upload_data_size, void **ptr)
86 {
87   static int aptr;
88   struct MHD_Response *response;
89   int ret;
90   FILE *file;
91   DIR *dir;
92   struct stat buf;
93   char emsg[1024];
94 
95   if (0 != strcmp (method, MHD_HTTP_METHOD_GET))
96     return MHD_NO;              /* unexpected method */
97   if (&aptr != *ptr)
98     {
99       /* do never respond on first call */
100       *ptr = &aptr;
101       return MHD_YES;
102     }
103   *ptr = NULL;                  /* reset when done */
104   if ( (0 == stat (&url[1], &buf)) &&
105        (S_ISREG (buf.st_mode)) )
106     file = fopen (&url[1], "rb");
107   else
108     file = NULL;
109   if (file == NULL)
110     {
111       dir = opendir (".");
112       if (dir == NULL)
113 	{
114 	  /* most likely cause: more concurrent requests than
115 	     available file descriptors / 2 */
116 	  snprintf (emsg,
117 		    sizeof (emsg),
118 		    "Failed to open directory `.': %s\n",
119 		    strerror (errno));
120 	  response = MHD_create_response_from_buffer (strlen (emsg),
121 						      emsg,
122 						      MHD_RESPMEM_MUST_COPY);
123 	  if (response == NULL)
124 	    return MHD_NO;
125 	  ret = MHD_queue_response (connection, MHD_HTTP_SERVICE_UNAVAILABLE, response);
126 	  MHD_destroy_response (response);
127 	}
128       else
129 	{
130 	  response = MHD_create_response_from_callback (MHD_SIZE_UNKNOWN,
131 							32 * 1024,
132 							&dir_reader,
133 							dir,
134 							&dir_free_callback);
135 	  if (response == NULL)
136 	    {
137 	      closedir (dir);
138 	      return MHD_NO;
139 	    }
140 	  ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
141 	  MHD_destroy_response (response);
142 	}
143     }
144   else
145     {
146       response = MHD_create_response_from_callback (buf.st_size, 32 * 1024,     /* 32k page size */
147                                                     &file_reader,
148                                                     file,
149                                                     &file_free_callback);
150       if (response == NULL)
151 	{
152 	  fclose (file);
153 	  return MHD_NO;
154 	}
155       ret = MHD_queue_response (connection, MHD_HTTP_OK, response);
156       MHD_destroy_response (response);
157     }
158   return ret;
159 }
160 
161 int
main(int argc,char * const * argv)162 main (int argc, char *const *argv)
163 {
164   struct MHD_Daemon *d;
165 
166   if (argc != 2)
167     {
168       printf ("%s PORT\n", argv[0]);
169       return 1;
170     }
171   d = MHD_start_daemon (MHD_USE_THREAD_PER_CONNECTION | MHD_USE_DEBUG,
172                         atoi (argv[1]),
173                         NULL, NULL, &ahc_echo, PAGE, MHD_OPTION_END);
174   if (d == NULL)
175     return 1;
176   (void) getc (stdin);
177   MHD_stop_daemon (d);
178   return 0;
179 }
180